The conventional method for making soybean milk comprises a step for washing of the beans, removing the skins of the beans by immersing them in water, and boiling and extracting by pressing under hydrothermal conditions.
This kind of manufacturing method makes the problems that about ⅓ of a bean is wasted in the form of a sludge, and at the same time, the nutrient component, including the fiber, the inorganic material etc., was discarded in the form of industrial waste.
To overcome the above problems, a patent (KR 1994-002528) was registered, in which is disclosed collection of the solid material comprising the bean curd dregs by using fermentation in order to solve the loss problem of this nutrient-containing component. And, furthermore a patent (KR 2001-41120) was registered, in which is disclosed to dissolve the solid material of the bean curd dregs by use of conjugated enzymes. However, the above methods have problems that the intrinsic malodorous smell and fishy taste of the beans is not eliminated; and it was also uneconomical to throw the expensive enzyme that are used in the production process for soymilk which is marketed at relatively low price.
Also, a patent (JP59-210861) was published to disclose the method for making soymilk in which an emulsion was mixed while heating, mechanically crushing after defacing the bean eliminating the soybean skin by dipping in water and homogenizing with high pressure.
Another patent (KR 10-0822165) was registered and it discloses a method for making a soymilk in which compressing of beans is carried out in a multi-stage operation using high pressure, while heating with steam, after removal of the bean skin during dipping in water and homogenizing dregs together.
However, all of the above methods need complicated processes with many items of equipment; the malodorous smell is not removed and they have not resolved problems of digesting due to the starch component of the bean; and, also, the prior art processes are unable to effect utilizing of the beans'skin which is containing the protein, the soy-oil and the dietary fiber, and this was rather lost as waste.
This is particularly problematic since in the skin of the black bean is contained, a glycitein, a superior anti-ageing component for the health improvement, but rather the soybean skin had been removed due to the lack of processing technology.
Moreover, a patent (KR10-2005-0068463) was released that discloses how to prepare a soft bean curd using live soy bean powder crushed from the raw beans and boiling with water, but this method has problems in which the bean powders are burning in the heating stage and one cannot make soymilk due to difficulties of filtering and coagulating of the starch of the beans after making the soymilk.
Accordingly, in all of the conventional methods for making soymilk using raw beans, with cooking by heating and squeezing, leaving unresolved the malodorous smell, the intrinsic fishy taste and grassy taste of the beans, as well as digesting problems due to the starch component of the beans. This is leading to customer dissatisfaction.